Bearing performance of a novel caisson-plate gravity anchor

Abstract

To provide a more reliable shared anchor for floating wind farms, a novel caisson-plate gravity anchor (CGA) is proposed. This design merges the benefits of both gravity anchors and suction caissons. Centrifuge model tests adopting only half of each anchor were carried out to study their bearing performance in sand. Additionally, particle image velocimetry (PIV) analyses were performed to monitor anchor movement and soil displacement. As supplementary data, numerical simulations with an advanced hypoplasticity model were also conducted to reveal the anchor capacity mobilisation mechanism. Findings indicate that the novel CGA possesses a significantly higher bearing capacity compared to standalone caisson or plate designs. By adding a plate above the caisson and increasing its weight, the anchor failure modes may shift from forward rotation to translational movement. Additionally, this adjustment may transition the brittle failure to a more reliable ductile failure. This augmented capacity of the CGA stems from the expanded soil mobilisation region and increased soil stress level in front of the caisson. The proposed CGA provides a promising solution for shared anchors in floating wind farms.